Life-history and Behavioural Adaptations to Flow Regime in Aquatic Insects

摘要

Evolutionary history determines how aquatic insects cope with extreme flow events, both natural and anthropogenic. From a macroevolutionary point of view, aquatic insects possess different modes of adaptation (morphological, behavioural, or life history) to cope with flow events. For example, some Ephemeroptera, Plecoptera and Trichoptera are adapted to long-term average cycles of flood and drought via life-history timing, while other groups with aquatic adults (Hemiptera and Coleoptera) may use rain-triggered behavioural responses to escape floods on a per-event basis. From a microevolutionary point of view, populations may also evolve in response to flow regimes at very local scales. Models of life-history and behavioural evolution illustrate howdisturbance regime characteristics (timing, frequency, predictability of events) and population structure (course- versus fine-grained, organism lifespan) determine how populations might evolve in response to different flood or drought regimes. All of these factors have implications for the structure of natural lotic insect communities, and for the effective management of dammed rivers and streams using ecological flows.